The present invention relates to a mechanism of converting the displacement direction of a slider driven by an electrostatic actuator in a structure which is manufactured on a surface of a substrate formed of silicon or the like by using a technology such as photolithography.
Hitherto, a slider (a shuttle) 52 has been displaced by using an interdigital electrostatic actuator 50 as shown in FIG. 6 in order to continuously control the displacement in a structure manufactured on the surface of a substrate formed of silicon or the like by using a technology such as photolithography.
The electrostatic actuator 50 comprises a fixed side interdigital electrode 54 and a movable side interdigital electrode 55, the movable side interdigital electrode 55 is mounted on a fitting portion 53 at an end of the slider 52, and the slider 52 is displaced in a direction parallel to a substrate surface 51 by generating the electrostatic force between the interdigital electrodes 54, 55.
In addition, in order to displace the slider in the perpendicular direction, a method of generating the electric field E perpendicular to the substrate surface 51 has been employed as shown in FIG. 7.
However, in a method using the conventional interdigital electrostatic actuator 50 or the like as shown in FIG. 6, the motion thereof is limited only in the horizontal direction with respect to the substrate surface 51 though the displacement can be continuously controlled, and no means which realizes the motion in the perpendicular direction with respect to the substrate surface 51 has been available.
Further, in a method of generating the electric field perpendicular to the substrate surface 51 as shown in FIG. 7, the displacement is small, and the continuous control is less easily implemented, and the slider cannot be displaced in a separating direction from the substrate surface.
The present invention has been made in light of the above problems, and a technical object is to provide a slider displacement direction conversion mechanism in the electrostatic actuator in which the displacement direction of the slider can be converted in the perpendicular direction with respect to the substrate surface.
Another technical object of the present invention is to provide a slider displacement direction conversion mechanism in the electrostatic actuator in which the displacement of the slider in the parallel direction with respect to the substrate surface is canceled, and the displacement in the upwardly perpendicular direction with respect to the substrate surface is increased.
In order to solve the above problems, the slider displacement direction conversion mechanism in the electrostatic actuator comprises at least one electrostatic actuator which generates the electrostatic force parallel to the substrate surface, at least one slider which is displaced under the force from the electrostatic actuator, and at least one elastic beam fixed to the substrate supporting the slider, the elastic beam has displaceable members which entirely or locally support the slider, and the displaceable members are characterized in that they are easily displaced in a direction different from the displacement direction when the slider is subjected to the force in the displacement direction.
The slider displacement direction conversion mechanism in the electrostatic actuator has preferably a leaf spring structure in which one end of the elastic beam is fixed to the substrate in an inclined manner to the substrate surface, and the other end thereof is fixed to the slider, the entire elastic beam is suitable for the displaceable members, the elastic beam has a strip-like projecting piece which is inclined to the substrate surface on both ends thereof, the strip-like projecting pieces on both ends form the displaceable member, and the elastic beam is fixed to the substrate via the other strip-like projecting piece.
Preferably, in the slider displacement direction conversion mechanism in the electrostatic actuator, the strip-like projecting piece is suitably formed by providing a notched portion in a part of the elastic beam, the displaceable member of the elastic beam is disposed so as to be easily displaced on a predetermined direction, and a plurality of elastic beams having the displaceable member are disposed so that each displaceable member is easily displaced in the same direction.
Preferably, in the slider displacement direction conversion mechanism in the electrostatic actuator, the displaceable member of the elastic beam is disposed so as to be easily displaced in a predetermined direction, a plurality of elastic beams having the displaceable members are disposed so as to support forward and rear portions of the slider, the forward and rear elastic beams are suitably disposed so that each displaceable member thereof is easily displaced in different directions, the slider comprises first and second sliders disposed parallel to each other, the first slider is supported by the substrate via the displaceable member of the elastic beam fixed to the substrate, the second slider is supported by the first slider via the displaceable member of the elastic beam, and driving forces in the reverse direction to each other are given from first and second electrostatic actuators to the first and second sliders so that the displacement in the direction parallel to the substrate surface of the second slider is canceled, and the displacement in the upwardly perpendicular direction with respect to the substrate surface is increased.
Preferably, in the slider displacement direction conversion mechanism in the electrostatic actuator, two of the first sliders are supported in parallel by the substrate via the displaceable member of the outer elastic beam fixed to the substrate, one of the second sliders is disposed between the two first sliders, the second slider is respectively supported by the two first sliders via the displaceable member of the inner elastic beam, the displaceable member of the outer elastic beam is a plate-like displaceable member inclined at a counterclockwise angle with respect to the substrate while the displaceable member of the inner elastic beam is a plate-like displaceable member inclined at a clockwise angle from the substrate.
When the electrostatic actuator generates the electrostatic force, the elastic beam supporting the sliders is subjected to the force to generate the displacement parallel to the substrate.
Since the displaceable members of the elastic beam supporting the slider are easily displaced in the direction different from the force applying direction, the displaceable members of the elastic beam are displaced by a specific angle with respect to the direction of the force.
As a result, the slider supported by the displaceable member of the elastic beam is displaced so as to have a component of the motion in the perpendicular direction with respect to the substrate.